Auto chrono 1 pt2

The world of tiny is upon me as I was tweezering along with the tiny hands for my seconds and Chrono dials. Everything looks so big in a picture, but then even under magnification, my eyes were squinting just trying to pick the things up. I’ve realized now that is partly because I’m only at 3.5x magnification and I need to be at 10x. It’s ok, I still look googly eyed….


However let me take a step back and show the little bits that’ll be making up this second watch assembly.  I have a case, dial, and hands all supplied by Ofrei.  The strap is from amazon by a company called Barton Watch Bands.  it has a nice easy access spring bar, making installation tool free.  The dark brown I felt paired well with the blue bezel & dial theme I was proceeding with.

The movement as noted in my Pt 1 of this was sourced off eBay.  The unit is an asian replica of the ETA 7750 movement.  First things first were to get it up in the holder and strip off the provided hands and dial.  I pulled a major facepalm on this and failed to remember that there were retention arms for holding the dial to the movement.  The dial still easily removed, but I felt quite silly once I had it off and forgot to flip the little arms out.

From here I wanted to pull the rotor of the rear so I could hold the movement a little better.  Sadly, I don’t have a legit 7750 movement holder, otherwise I could be a bit more secure in what I do, but it is what it is.  Assuming I do more like this, I’ll certainly make something.  With the dial off, and flipped over, I quickly heard the slip out of the Day Dial.  I didn’t nab any pictures of this, but I quickly realized how I needed to reinstall this, as it’s held in place with a bit of pressure from the rotating gear.

Oscillating weight removed

From here I placed my dial (making sure to open the dial feet retention arms) and began the daunting (for me) task of placing hands.  I quickly realized that a few things I have are quite inadequate.  My tweezers weren’t delicate enough.  My movement holder doesn’t hold the movement as square as I’d like.  And worst of all, my hand press tool, while the main unit isn’t bad, the business end details are utter garbage.  The plastic is mushed over, so they definitely aren’t pushing on the hands squarely.  It’s close, but when you’re staring at these tiny things, zoomed in to the moon, you want precision.  I’m sure a more seasoned hand works well without this stuff, but different strokes for different folks.


One down, five to go.

Once I got the subdials done, the main hands went incredibly quickly.  It felt like I was zooming along.

My Chronograph Seconds hand was a bit long for my case & dial, so I had to do some trim work.  Super secret tool used here was a nice set of nail clippers.  Where the hand rests in the case, you’ll never see the bare end.

It was around here, when I went to begin adjusting the length of my stem that I realized that the stem included with my movement was NOT what it was supposed to be.  The diameter of the stem is 0.9mm, and my case requires a 1.2mm stem.  NOt much, but enough to have a minor hold up with things.  I’m still waiting on a new shipment of one off eBay, as it seems USPS has lost the stem.  Such is life.

In the interim, I added some personal details to the oscillating weight, though I’m a bit bummed in what happened with our Laser.  I had modeled up the weight in solidworks along with our old family name & a logo representative of my daughter.  All was well in 3D, however when I lasered onto the weight, the scale was not quite right.  I’ll know for future ones, and likely order a replacement so I can do it correctly.  Despite this not being an exhibition back case, it still kinda bugs me.  Still looks nice though otherwise.

So while I couldn’t finish my stem, I decided I’d still wind the watch up, set the date and assemble (sans stem) just so I could get a feel for the watch assembled, and see if anything else unexpected creeped up on me.  The finish of it all was something that I quite enjoyed.

Unfortunately it was about 10 minutes after this, that I realized there was a fatal issue.  When resetting the chrono, the second hand would slip on its shaft.  Annoying, but I knew I could remedy.  I brought out the staking set and went about to compress the mating shaft on the second hand.

I should note that by this point, I’ve also snagged a 10x loupe as well as some much better tweezers.  Yah, the tweezers were still amazon specials, but for the 12$ they cost, I figured I’d give them a shot.  I quickly realized as well that I am terrible at holding a loupe to my face.  I also realized that while my staking set went to very small sizes, it didn’t get small enough.  Some quick research turned up that my options were to either compress the tube somehow, or glue.  I opted for the latter, as I felt I could get a tiny dot of superglue on the face, and given that the stem was a press fit on the shaft, it wouldn’t allow the glue to wick down into the movement.  The result was a second hand that stays put.

I’ll update this with some pictures & such when I get the new stem in…..if it ever shows up.